Technology:Phytoremediation
- Combination of phytoextraction (for treatment of four areas with high lead concentrations - Areas 1-4) and phytostabilization (for treatment of one area with low lead concentrations - Area 5) to reduce total soil lead concentrations and SPLP extractable lead
- Soils were fertilized with nitrogen, phosphorus, and potassium; dolomite lime was added to adjust soil pH
- Fertilizers and lime were tilled into the soil to a depth of 15 to 20 cm; an overhead irrigation system was used to provide moisture
- Areas 1-5 were seeded with Indian mustard and sunflower; 3 treatment crops were planted
- Supplemental foliar fertilizers were added through the irrigation system
- Area 5 also treated with stabilizing amendments

Cleanup Authority:Not identified

Site Contact:
Not identified

Regulator:
Not Identified

Contaminants:Lead
- Average concentration of total lead was 635 mg/kg; concentrations were higher than 1,000 mg/kg in many areas of the site, with some areas exceeding 4,000 mg/kg
- Leachable lead concentrations were higher than 0.015 mg/L using the Synthetic Precipitation Leaching Procedure (SPLP)

Waste Source:Open burn and open detonation

Type/Quantity of Media Treated:Soil
- Soil type is silty loam with a pH of 6.5 to 7.5
- Water table ranges in depth from 2 to 4 ft below surface soil
- Site drainage is poor; soil remains saturated throughout the growing season (April to October)

Purpose/Significance of Application:Phytoremediation of lead in soil using both phytoextraction and phytostabilization

Results:- Plant growth for each of the treatment crops was generally good
- Some areas within the treatment area remained saturated; these areas exhibited poor plant growth and reduced biomass yields
- Total lead concentrations in Areas 1-4 decreased from an average of 635 mg/kg (4/98) to 478 mg/kg (10/98); by 10/98, the highest concentrations in Areas 1-4 had been reduced
- Lead uptake ranged from 342 mg/kg (dry weight) in the Indian mustard in treatment crop 1 to 3252 mg/kg in the Indian mustard in treatment crop 3
- Average lead uptake measured in the sunflower plant material and Indian mustard were similar, having average lead concentrations from all crops of approximately 1000 mg/kg (dry weight).
- The average reduction in SPLP lead concentration in Area 5 was 0.95 mg/L

Cost Factors:Not provided

Description:The Ensign-Bickford Company in Simsbury, Connecticut, conducted open burn/open detonation (OB/OD) activities, resulting in near surface soils in the area becoming contaminated with lead. From 1996 to 1997, Edenspace Systems Corp. (formerly known as Phytotech, Inc.) conducted phytoremediation treatment of a 1.5 acre area surrounding the OB/OD area. In 1998, this effort was expanded to include a total of 2.35 acres and to address not only reductions in total lead concentrations, but also stabilizing leachable lead in the soil.

Phytoremediation was conducted using three treatment crops of Indian mustard and sunflower over a six month period. Total lead concentrations in a portion of the site decreased from an average of 635 mg/kg (4/98) to 478 mg/kg, with hot spots also reduced. In the area where phytostabilization also was used, the average reduction in SPLP lead concentration was 0.95 mg/L. Further treatment is planned during 1999 and 2000.